Fair Value Measurements And Derivative Instruments Reporting (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers between levels	$ 0		$ 0
Impairment - goodwill and intangible assets			35,121,000
Cash equivalents	0		0		$ 0
Interest expense	$ 10,587,000	$ 1,427,000	32,538,000	$ 4,083,000
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment - goodwill and intangible assets			1,000,000.0
Fair Value, Nonrecurring [Member] | COVID 19 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment - goodwill and intangible assets			$ 34,100,000
Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest expense		$ 200,000		$ 700,000
Minimum [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Customer attrition rates and discount rates			11.00%
Maximum [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Customer attrition rates and discount rates			16.00%